一、JSP頁面
<td>
<input id="verificationCode" name="verificationCode" type="text" value="" class="input_bg"/>
</td>
<td width="6%">
<canvas id="canvas" width="100" height="30"></canvas>
</td>
二、css樣式
#canvas{
float:right;
display: inline-block;
border:1px solid #ccc;
border-radius: 5px;
cursor: pointer;
}
三、生成驗證碼的js文件(核心)
var yzm;
function draw(show_num) {
var canvas_width=$('#canvas').width();
var canvas_height=$('#canvas').height();
var canvas = document.getElementById("canvas");//獲取到canvas的對象,演員
var context = canvas.getContext("2d");//獲取到canvas畫圖的環境,演員表演的舞臺
canvas.width = canvas_width;
canvas.height = canvas_height;
var sCode = "A,B,C,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,W,X,Y,Z,1,2,3,4,5,6,7,8,9";
var aCode = sCode.split(",");
var aLength = aCode.length;//獲取到數組的長度
for (var i = 0; i <= 3; i++) {
var j = Math.floor(Math.random() * aLength);//獲取到隨機的索引值
var deg = Math.random() * 30 * Math.PI / 180;//產生0~30之間的隨機弧度
var txt = aCode[j];//得到隨機的一個內容
show_num[i] = txt.toLowerCase();
var x = 10 + i * 20;//文字在canvas上的x座標
var y = 20 + Math.random() * 8;//文字在canvas上的y座標
context.font = "bold 23px 微軟雅黑";
context.translate(x, y);
context.rotate(deg);
context.fillStyle = randomColor();
context.fillText(txt, 0, 0);
context.rotate(-deg);
context.translate(-x, -y);
}
for (var i = 0; i <= 2; i++) { //驗證碼上顯示線條
context.strokeStyle = randomColor();
context.beginPath();
context.moveTo(Math.random() * canvas_width, Math.random() * canvas_height);
context.lineTo(Math.random() * canvas_width, Math.random() * canvas_height);
context.stroke();
}
for (var i = 0; i <= 40; i++) { //驗證碼上顯示小點
context.strokeStyle = randomColor();
context.beginPath();
var x = Math.random() * canvas_width;
var y = Math.random() * canvas_height;
context.moveTo(x, y);
context.lineTo(x + 1, y + 1);
context.stroke();
}
yzm=show_num;
}
function randomColor() {//得到隨機的顏色值
var r = Math.floor(Math.random() * 256);
var g = Math.floor(Math.random() * 256);
var b = Math.floor(Math.random() * 256);
return "rgb(" + r + "," + g + "," + b + ")";
}
四、登錄的js
1.點擊更新驗證碼
$("#canvas").on('click',function(){
draw(show_num);
});
2.判斷驗證碼是否正確
//得到驗證碼的內容
var num = yzm.join("");
//得到輸入的內容
var verificationCode = $("#verificationCode").val().toLowerCase();
//判斷驗證碼是否爲空
if(verificationCode.replace(/(^\s*)|(\s*$)/g, "") == ""){
alert("驗證碼不能爲空!");
$("#verificationCode").focus();
return false;
}
//判斷驗證碼是否正確
if(verificationCode!=num){
alert("驗證碼輸入錯誤,請重新輸入!");
$("#verificationCode").val("");
$("#verificationCode").focus();
return false;
}